Using PHP interfaces in Codeigniter

Question

I am trying to find out how can I used PHP interfaces in my MVC design. I want to make sure that the design enforces an interface so that any new module would follow that.

For example:

<?php

interface BaseAPI {
     public function postMessage($msg);
}

class ServiceAPI implements BaseAPI {
     public function postMessage($msg) { return $msg; }
}

class Service_Two_API implements BaseAPI {
     public function postMessage($msg) { return "can't do this: ".$msg; }
}

?>

I want to do this in CI. Is it possible? how should I design it?

Answer 1

Here's How to Get CodeIgniter to Load Interfaces Properly

In your application/config/autoload.php:

// Add "interface_autoloader" to your models array
$autoload['model'] = array('interface_autoloader');

Now create a new class in your application/models folder "interface_autoloader.php":

<?php

class Interface_autoloader {

    public function __construct() {
        $this->init_autoloader();
    }

    private function init_autoloader(){
        spl_autoload_register(function($classname){
            if( strpos($classname,'interface') !== false ){
                strtolower($classname);
                require('application/interfaces/'.$classname.'.php');
            }
        });
    }

}

Now create a new folder in your application folder called "interfaces":

Then just add your interfaces into the "interfaces" folder and you should be able to use them like normal.